The 6-phenoxy picolinic acid alkylidene hydrazide derivative according to the present invention is a novel compound which has never been described in any literature.
Hitherto, it has been highly demanded to provide a herbicide capable of lessening the amount existing or remaining in environment after use and exhibiting an excellent herbicidal effect even when used in a small amount; a herbicide capable of exhibiting an excellent herbicidal effect with a high selectivity between crops and weeds irrespective of change of environmental conditions; and a herbicide which is free from phytotoxicity or chemical injury even upon the succeeding crop of double cropping.